Transmission (62TE) Stall Fix - All roads lead to rebuild
Hell I'm just documenting the journey I went through doing my first ever transmission rebuild.
SYMPTOMS:
So to start the symptoms that I was dealing with is that when the van would come to a stop in park or reverse the engine RPM would shutter down a little bit and then stall.
People would assume it's the engine but it would only stall in drive or reverse. And I left it in Park or Neutral. I could idle for hours no problem. And also while I was driving around town or on the highway, it shifted perfectly fine. If I popped it into neutral before coming to a stop nothing would happen.
TESTING:
So I grabbed my scan tool to check the data points. When I looked at the transmission data, the one that stood out the most was that the "turbine speed" would randomly blip 200 to 300 RPM as the engine was shuttering down. When you're fully stopped in drive or reverse, the turbine speed should always read 0.
So for my initial research, I thought it was related to the torque converter clutch. Whether the clutch itself or a valve or a solenoid.
FIX ATTEMPTS
1st ATTEMPT:
So the first easiest and cheapest fix is to replace the TCC VFS. I popped off the side cover, replaced the solenoid, put everything back together and it still had the same symptoms.
2nd ATTEMPT:
So then I decided to take the entire valve body off and do a whole rebuild with all new solenoids and using a vacuum pump to vacuum check all of the valves. Using a testing guide I found on Sonnax's website, I checked all the valves and found that one of the TCC related valves was reading a little low meaning that that one valve could be down on pressure or have a leak. So I replaced it with a new valve and it was perfectly fine. I put everything back together but still the same issue.
3rd ATTEMPT:
Then my next course of action was to tackle the torque converter. But low and behold right before I dropped the transmission. The flex plate snapped. So there was a chance that for who-knows-how-long the flexplate could have been partially snapped causing the torque converter to wobble.
So when I dropped the transmission I replaced the flex plate, torque converter, and front pump. I then put it all back together and still have the same symptoms.
REBUILD:
Now at this point I decided to just do a whole rebuild. I replaced every seal, every gasket, every o-ring, every clutch, every steel, and every piston.
But while I was rebuilding it, I noticed that none of the steels and clutches looked worn out or over heated. The only thing that I would say was the smoking gun is that when I rebuilt the input drum ( the drum that holds underdrive, overdrive, and reverse) I noticed that the input shaft had a little lateral play to it. A little left to right looseness. So I decided to get a new input drum housing. And when I swapped over all the components the shaft was tight. No end play at all.
And so I think that could have been the issue. A loose input shaft could have caused the input drum to have excessive wobble at low RPM. And if the input drum is wobbling, it could have caused the 2/4 clutch that is just past the input drum to partially engage. But I'm not an expert so this is just an assumption
CONCLUSION:
So overall, if your van is stalling when you come to a stop and drive or reverse, try replacing your VFS solenoid. If that doesn't work then you're going to have to drop the transmission and possibly just throw the book at it. New torque converter and rebuild.
For me, my goal was to firstly learn about this transmission and secondly try to fix it for as cheap as possible. I think overall I spent about $1,200 in parts. And that includes torque converter, front pump, solenoids, rebuild kit with all of the clutches and steels, all pistons, and input drum housing.
If any of you guys want to see some of my videos on it, you can follow my social medias by checking on my link tree.